What is the definition of exon in biology?

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

Restriction enzymes are used in making recombinant dna. describe the role restriction enzymes perform when constructing recombinant dna.

During a fierce storm a large number of tall trees on an island are uprooted by the wind and die. most of the trees on the island are now short trees and produce seeds that grow into short trees. what concept is shown in this example? question 5 options: natural selection artificial selection genetic engineering gene splicing